According to the prior art, the bicycle head bowl bearing is located by means of the front fork upright tube which is provided at the top thereof with threads engageable with a pressing element, which works to locate the bearing in conjunction with a fastening member. Such a fastening means of the prior art as described above has inherent shortcomings, which are expounded explicitly hereinafter.
The structural strength of the front fork upright tube is undermined by the threads which are located at the top of the front fork upright tube. As a result, the front fork upright tube is vulnerable to deformation or crack when the handlebar upright tube is inserted into the front fork upright tube.
It is rather inconvenient and time-consuming to fasten the bearing which has become loosened, in view of the fact that the work of fastening the loosened bearing calls for the use of a hand tool, such as a wrench.
It is difficult to make a microadjustment of the bearing by means of a hand tool.